提出了超高效液相色谱-三重四极杆质谱法(UHPLC-MS/MS)同时测定化妆品中13种α-羟基酸含量的方法。样品0.2 g经水超声提取30 min(不易分散样品经异丙醇分散均匀后用水超声提取),提取液经离心过滤后采用UHPLC-MS/MS分析,13种目标物在Agilent Zorbax RRHD SB-Aq C₁₈色谱柱上分离,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈混合液为流动相进行梯度洗脱,质谱分析采用电喷雾离子源,负离子、多反应监测模式采集。结果表明:13种α-羟基酸的质量浓度在一定范围内与对应的峰面积呈线性关系,羟基辛酸、二苯乙醇酸、α-羟基癸酸的检出限(3S/N)为0.030 μg·g^-1,羟基乙酸、乳酸的检出限(3S/N)为3.0 μg·g^-1,其余8种α-羟基酸的检出限均为0.30 μg·g^-1。按照标准加入法进行回收试验,回收率为85.1%~114%,测定值的相对标准偏差(n=6)均小于10%。方法用于分析20批样品,α-羟基酸检出总量为20~6 800 mg/100 g,仅有1批α-羟基酸总量超标。

A method was proposed for simultaneous determination of 13 α-hydroxy acids in cosmetics by ultra-high performance liquid chromatography triple quadrupole mass spectrometry (UHPLC-MS/MS). The sample(0.2 g) was extracted for 30 min in water by ultrasonic, while the undispersed samples added isopropanol firstly. After centrifuging and filtering, the extracted solution was analyzed by UHPLC-MS/MS. The saparation of 13 target compounds was performed on a Agilent Zorbax RRHD SB-Aq C₁₈ column, using mixtures of 0.1% (volume fraction) formic acid solution and acetonitrile at different volume ratios as mobile phases for gradient elution. Electrospray ion (ESI) source with multiple reaction monitoring (MRM) mode in the negative ion mode were adopted in MS analysis. As shown by the results, linear relationships between values of peak area and mass concentration of 13 α-hydroxy acids were found in definite ranges, with detection limits (3S/N) of 0.030 μg·g^-1 for hydroxycaprylic acid, benzilic acid, and α-hydroxy-decanoic acid, 3.0 μg·g^-1 for glycolic acid and lactic acid, and 0.30 μg·g^-1 for the other 8 α-hydroxy acids. Test for recovery was made by standard addition method, giving results in the range of 85.1%-114%, with RSDs (n=6) of the determined values less than 10%. This method was applied to the analysis of 20 samples, with the total amounts of α-hydroxy acids in the range of 20-6 800 mg/100 g, which were all in standard permission scope except an exceeding sample.